early blight: influence of different varieties · euroblight workshop, bologna, 2-5 may 2007 thanks...
TRANSCRIPT
EuroBlight Workshop, Bologna, 2-5 May 2007
Early Blight:
Influence of different varieties
J. Leiminger, H. Hausladen
Early blight -review 2006
• Increasing diseases of early blight in Germany and also in Europe
• nationwide monitoring documents rising occurence of early blight
• Disease with significant yield losses; Germany 30%
• First early blight symptoms in june
• Slowly epidemic development of early blight due to hot temperatures in june and july with very low moisture and rainfall
• Strong increase of early and late blight during august
material and methods
• field trails with 8 potato varieties within different maturity groups
early : Karlena (S), Marabell (S)
medium: Solara (S), Agria (S), Albatros (W)
late: Logo (W), Maxilla (W), Kuras (W)
• weekly fungicide treatments
• trials:
control, Coverspray, Mancozeb (Max), Amistar-Shirlan (Max)
• weekly ratings done on single plants
• estimation of yield, starch content and tuber sortation
material and methodsrating:
• weekly rating of the necrotic leaf area
• rating of: early blight, late blight,
total necrosis: unspezific necrosis, seneszenz,
• 10 plants out of each replication
Upper leaf level
Main/middle leaf level
Lower leaf level
AUDPC in different varities - untreated
0
500
1000
1500
2000
2500
3000
3500
4000
Karlena Marabell Solara Albatros Agria Maxilla Logo Kuras
AU
DPC
(% &
Tag
)
location Weihenstephan 2006
comparison of varities: AUDPC Kuras,Logo, Maxilla
0
500
1000
1500
2000
2500
3000
AlternariaKontrolle
Amistar/ShirlanMaximal
MancozebMaximal
AlternariaKontrolle
Amistar/ShirlanMaximal
MancozebMaximal
AlternariaKontrolle
Amistar/ShirlanMaximal
MancozebMaximal
Kuras Logo Maxilla
AU
DPC
(% &
Tag
)
Field trial: Sept. 1st, 2006
Solara Kuras
Mancozeb
Azoxystrobin
Ranman
control
Ranman
control
AzoxystrobinMancozeb
Field trial: Sept 20th, 2006
Solara KurasRanman
control
Mancozeb Azoxystrobin
Ranmancontrol
Azoxystrobin
Mancozeb
Alternariayield
estimation of:
• tuber yield
• tuber size (<35, 35-55, >55)
• starch content
sortation Kuras
0
100
200
300
400
500
600
700
800
< 35 mm 35-55 mm >55 mm total
sortation
yiel
d dt
/ha
controlCoversprayAmistar/ShirlanMancozeb
+ 20,7%+ 11,6%
aaaaaaaa a a aa a a abc
Starch yield industrial varieties
0
20
40
60
80
100
120
140
160
180
Albatros Maxilla Logo Kuras
variety
star
ch y
ield
dt/h
a
controlcontrol early blightAmistar/ShirlanMancozeb
+ 22,8% + 27,5%+ 29,5%
+ 34,2%
conclusion
• All tested varieties showed medium to high susceptibility againstearly blight
• Early maturing varieties showed higher incidence in disease severity of early blight as late maturing varieties
• Variety-dependend differences concerning early blight susceptibilitywere detected within the maturity group
• Early blight affects yield relevant factors: tuber yield, starch content,tuber size
• By the use of Azoystrobin tuber yield and starch content was significantly increased in comparison to application of mancozeb
EuroBlight Workshop , Bologna, 2-5 May 2007
Thanks for your attention !